Is this how World War III begins — not with an assassination or a nation-state invading its neighbors but with an arc of chaos stretching over 3,000 miles from Tripoli to Kabul?

Deep into this summer of global turmoil, with the United States once again seeking to steer the course of events in Iraq with precision-guided missiles, my thoughts have turned to the late historian Tony Judt. In a brief but brilliant essay written for The New Republic hours after the 9/11 attacks (not available online), Judt described gazing out his downtown-facing New York University office window that late summer morning to watch the 21st century begin.

The prevailing geopolitical dynamic of the coming century, he argued, would be disintegration.

And so it has been. Nearly 13 years later, the international order painstakingly constructed by the United States in the years following World War II has begun to crumble. That order survived and expanded its reach throughout the Cold War because both superpowers played by the traditional rules of international relations, despite the intensity of their ideological conflict. The U.S. and the Soviets were engaged in a national rivalry on an international scale, with nearly all the countries of the world compelled to join sides. And as the American side flourished, so, too, did the institutions it founded and funded throughout the West and in those regions of the developing world that joined the anti-Communist side of the Cold War.

It was partially inertia that led this order to persist and expand further for more than a decade following the collapse of the USSR. But by September 2001 (if not before), we had turned a corner into a new reality, one in which insurgent forces throughout the Middle East, northern Africa, and South Asia would attack key elements of the international order. Not laterally, as the Soviets once did and Vladimir Putin's Russia is doing now in Ukraine, but from below, using the asymmetrical warfare of mass terrorism.

From al Qaeda to ISIS, these groups have had two main targets. One is America and its global leadership as expressed through international institutions (the U.N., IMF, World Bank, USAID, NGOs, etc.). Another is the nation-states created by the colonial powers after World War I, long ruled by autocrats and dictators who were sustained by those American-led international institutions.

The question is how the U.S. should respond to this challenge to the international order. To judge by our words and actions from 9/11 right down to President Obama's latest statements and policies, we haven't got a clue.

On one side are the neoconservatives. One might think that their identification with the Iraq War and the bloody, unpopular, nearly decade-long occupation that followed it would have discredited the neocons. But to judge by the influence they continue to exercise on Republicans and Democrats alike, it hasn't.

There are at least two reasons. As military maximalists, the neocons are always able to respond to a failure by suggesting that things would have turned out better if only more force had been used. The problem, then, is never the policy itself but merely its insufficiently tough-minded execution. In this respect, neocon ideas are empirically unfalsifiable.

Then there's the simplicity and coherence of the neocon reading of history — qualities that were on full display in Robert Kagan's much-discussed cover story in The New Republic last May. The essay elegantly (and flatteringly) portrayed the U.S. as the singular guarantor of world order since the end of World War II. Without the ample use of American military might to impose and sustain that order, chaos would have reigned in the past — and will reign again in the future, if Barack Obama and his successor fail to fight it militarily. As events this summer have spun out of control from Kiev to Mosul, Kagan's late-spring predictions have appeared to receive lightning-fast confirmation.

So is more active military engagement the answer? Can the United States use force to bring stability to Libya, Syria, Iraq, and Afghanistan, and thereby prop up the crumbling international order?

Sure. All it would take is millions of troops and an occupation of indefinite duration. Think of George W. Bush's Iraq surge times 10 — or 20.

Needless to say, America has neither the will nor the resources to attempt anything remotely like this. Especially because the occupied Muslim populations would be exceedingly unlikely to appreciate the humiliation of long-term occupation by a foreign, Western, Judeo-Christian power. Our very efforts to bring peace and order would fuel the very insurgency we'd be trying to combat. (This is of course precisely what happened in Iraq from 2003 to 2007.)

At the other extreme are those who would prefer dramatic American withdrawal from the world. Their critics call them isolationists, but those who defend this position (Bernie Sanders on the left; Rand Paul on the right) prefer to call themselves realists who define U.S. national interests much more narrowly than neocons typically do.

Whatever we call them, this faction (with which I have been known to ally myself from time to time) appears willing to support standing back to watch the world burn from the relative safety of our own shores. It is a course of inaction that would require much greater acceptance of global injustice and suffering than Americans (or at least their governing class) have been willing to tolerate in recent decades. It might also greatly hasten the breakdown of international order that is already well underway.

As in so much else, President Obama's instincts are to seek a middle course between extremes. Accordingly, he wants the U.S. to maintain global order (a neocon goal), but he wants to do so with a light footprint and without expending vast amounts of blood and treasure (realist means).

Obama would like us to see this as prudent statecraft. But it could more accurately be described as a childish refusal to accept the need for necessary trade-offs.

Take our new bombing policy in Iraq. If our goal is to protect the Yazidis, bolster the hand of the Kurds, and temporarily slow down ISIS's advance across northwestern Iraq, then surgical strikes might make a difference. Indeed, it appears they already have.

But beyond that? ISIS is ruthless and well funded. It controls considerable territory in both Iraq and Syria. It's feeding off of Sunni resentment of the Shia government of Iraqi Prime Minister Nuri al-Maliki, who, despite American arm twisting, seems disinclined to give up power quickly or easily. Until he does, the formation of a less sectarian government will be impossible.

Unless we are willing to depose Maliki, reoccupy the country with hundreds of thousands of troops, impose order with overwhelming force, and accept the resulting casualties and blowback, the situation is exceedingly unlikely to improve in any serious way.

Short of that, we could of course focus on protecting Iraq's Kurdish regions. But that might hasten the dissolution of the nation, leading to an increase in violence throughout the rest of the country. Renewed calls for outright Kurdish independence could also end up stirring unrest and violence in Kurdish areas just over the Turkish border.

One definition of tragedy is a situation in which there are no good options, in which every conceivable course of action — no less than the choice to do nothing at all — seems to make things worse or merely defer inevitable heartbreak and suffering.

Americans, incorrigibly optimistic, are famously averse to tragedy. Which means that we're unlikely to respond well to the rapidly multiplying tragedies of our time.

But that doesn't mean the tragedies can be waved away with bombs and good intentions.